Techniques have been devised, and equipment has been used, to remove, in a liquid carrier, volatile components from less volatile components. For example, processing, disposal, or handling parameters may require that solvents (volatile components) be removed from those less volatile components in a chemical composition. Where the volatile component to be removed from the less volatile solid components is water, the process is referred to as drying or dehydrating.
With specific reference to drying, it has been known to use spray-drying, where the water is flash-evaporated, or to use mechanical dryers, such as evaporators. For example, U.S. Pat. No. 2,887,390 to Coulter et al discloses the use of a venturi tube for delivering hot drying gas to a drying chamber. Feedstock, such as evaporated milk, is supplied by "liquid delivery means" to the throat of the venturi tube, and preferably "slightly upstream" from the narrowest portion of the throat. With this system, the rate of delivery of feedstock must be limited to avoid impingement milk particles on the interior surfaces of the venturi tube. Moreover, the feedstock is discharged into the venturi where the gas flow is laminar, rather than turbulent. These two factors limit the capacity and efficiency of drying apparatus constructed and operated in accordance with the Coulter et al disclosure. In addition, the Coulter et al system depends entirely on the gas flow to atomize the feedstock, resulting in droplets being formed at irregular rates and in a wide range of sizes.
While the above techniques are satisfactory in some applications, for certain products or applications these methods are not economical, result in degradation of the product, or simply cannot be used. A specific group of products which has evaded efforts for economical dehydration includes corn sweeteners, including high-fructose corn sweeteners (HFCS), citrus and vegetable products, xanthan gum, and the like.
Caloric sweeteners are typically either sucrose, derived from sugar cane and beets, or dextrose or fructose sweeteners, derived from fruit and corn. When the starch present in corn is subjected to hydrolysis, dextrose, and higher saccharides are produced. Such corn sweeteners are often referred to by their DE (dextrose equivalent) and usually fall in the range of between 36 DE and 95 DE corn syrups. If the dextrose and higher saccharides are subjected to isomerization via a process including certain enzymes, dextrose, fructose and higher saccharides are produced. A typical example after isomerization of the product may be represented by 42% fructose based upon dry solids content. This product can further be refined via chromatographic separation to yield a 90-95% or higher percentage fructose product. These high-fructose corn syrups (HFCS) may be used as sweeteners, or blended with corn sweeteners (dextrose sweeteners) for whatever purposes.
The use of HFCS has grown, on a per capita basis, from 0.7 lb. in 1970 to 29.8 lbs. in 1983. This rise in the use of HFCS is based to a great extent on the almost complete switch over to HFCS from sugar by the carbonated beverages industry. Since HFCS is sweeter, less is used, and, accordingly, cost savings can be realized. However, the use of HFCS has leveled off recently, indicating a mature market. HFCS consumption would increase, and compete with sugar, if HFCS is available in a dry, amorphous, powder form. This invention provides such a product.
As stated above, HFCS is derived from corn and is typically available between 42% and 90% fructose (dry weight basis). The syrups can vary from 71% to 80% dry solids, as an example. Sweetness of these HFCS products closely approximate that of sucrose. One processor has produced crystalline fructose (100% fructose dry basis) from HFCS for specialty markets. However, due to the processing required, the crystalline fructose is many times more expensive than cane or beet sugar and, hence, has failed to overtake sugar in many markets. Dry, flowable 42%, 55%, and/or 90% HFCS corn syrup solids, or blends thereof with dextrose corn syrup solids, economically produced, would displace sugar in many markets. For example, for baked foods, such as those made from cake mixes, dry, powdered HFCS or blends thereof could provide sweetness and, because HFCS is hygroscopic, would desirably retain moistness for the prepared food. Of course, this is by way of example only, since a dry, flowable, amorphous (noncrystal) HFCS sweetener or blend could enter many other markets.
Attempts have been made to dry corn syrups and HFCS. However, to date, such attempts have failed, or have, for whatever reason, including economics, been discontinued. For example, Lundquist, Jr. et al, U.S. Pat. No. 3,956,009, discloses a method for drying fructose solutions using a spray-drying technique in which solid crystalline fructose particles are interjected as feedstock into the product. HFCS is a particularly troublesome product. It is highly temperature-sensitive. High temperatures can degrade the fructose and caramelize the product. Moreover, due to its hygroscopic nature, it is difficult to handle.